The design specifications for the ice station on the Brunt ice shelf are among the most exacting on the planet.

It must it be home to a crew of scientists that dwindles to 16 in the southern hemisphere winter, when there is no daylight for three months, and booms to 60 in the summer.

It has to rise above the 1.5 metres of snow that falls each year.

At the same time every nut and bolt must be shipped in and, when the station comes to the end of its anticipated 20-year life, everything must be shipped out again to leave no trace of its existence on the pristine continent.

Four of the previous Halley ice stations dating back to the 1950s have slowly been buried by the snow and crushed by the ice as it travels north-west at the rate of 400 metres a year.

The iceberg also gradually breaks up at its seaward edge.

The Halley V station it will replace by December 2008 also has adjustable legs and is the only one not to have been buried.

However, it faces another problem.

Scientists predict that the ice shelf will halve within the next decade and the section of ice on which Halley V sits will simply float away.

The new, towable ice station should be able to avoid such problems by simply moving out of the danger area, allowing scientists to carry on vital research at the site where the hole in the ozone layer was first discovered.